The following is my answer to the question of how to deal with the serial number of your ordinary invoice, and what to do if the customer can't get it back: Hello, dear! There are two ways to deal with it: first, contact the customer and tell the other party that the invoice number is wrong and can't be used normally, and all the copies of the invoice will be withdrawn, invalidated and reopened; Second, write off by issuing red-ink invoices, and then reopen them: (1) There are three situations that need to issue red-ink special VAT invoices: (1) After the buyer's certification is consistent, sales are returned, invoicing is wrong, taxable services are terminated, etc., but they do not meet the conditions for invoice invalidation, or red-ink invoices need to be issued because of partial sales return and sales discount; (2) The special invoice obtained by the buyer is not used to declare deduction, but the invoice copy or deduction copy cannot be returned;